Comparing physicochemical properties related to thermal stability of caprine and bovine milk protein concentrate dispersions

Abstract

Thermal stability and physicochemical properties as a function of heating temperature, pH and salt addition was compared between caprine and bovine milk protein concentrate dispersions. Caprine milk protein concentrate (MPC) had a lower amount of heat coagulation time and a higher percentage of sediments than bovine MPC. Calcium ion activity of caprine MPC was higher than that of bovine. The amount of κ-casein in the serum of caprine MPC dispersions was higher than that of bovine, and increased with increasing temperatures, pH and the addition of NaCl and citrate. The amount of whey protein in serum was also higher in heated caprine MPC compared with bovine. Particle size of caprine MPC was larger than bovine MPC and was more susceptible to induced aggregation. The lower thermal stability of caprine MPC might be associated with the higher calcium ion activity and the higher amount of κ-casein dissociation promoted by whey protein denaturation and complexation in serum.